The issue I am experiencing is related to the network card performance. I've noticed that with default configuration (auto negotiation speed and duplex) I was able to reach only 30Mbps of my broadband connection, while normally I could get 120Mbps (with my previous computer).

I've asked the ISP to check my network connection. The technican came with his notebook, connected to my router and show me that ftp transfer from some sites are at maximum speed 120Mbps.

After he left, I tried to investigate what is wrong with my computer and after googling I decided to switch manually to 100Mbps and full duplex speed of the network card on my computer. After that I was able to reach maximum 10MBps - so it was 100% maximum of the current speed - bravo!.

The problem is that the remaining 20Mbps out of my broadband connection is now not reachable for me due to static settings of 100Mbps. Now, I would like to switch back to 1Gbps of my NIC, but there is a degraded performance of this NIC, and there is a lot of similar messages in the Internet published by other people having the same issue.

Are you able to provide the solution of this issue? Why the default configuration does not work. Why this NIC is not able to operate at the normal 1Gbps speed.

PS. setting "Large Send Offload version no 2" to NO helps to reach extra 5 - 10 Mbps - but this is still much less than expected (120Mbps)